Suction valve for reciprocating compressor

ABSTRACT

A suction valve for reciprocating compressor includes a fixation part, which receives a driving force of a reciprocating motor, and is fixed-combined to the front end surface of a piston performing linear reciprocal movement in the cylinder, a switching part for switching a hollow channel formed to penetrate the piston having a certain area, and a plurality of arms for connecting the switching part and the fixation part to make the switching unit behave in a certain displacement section having the fixation part as a fixed point. Receiving driving force of the reciprocating motor, the piston is bent and straighten by the pressure difference, and stress is distributed evenly in the above process, and minimizing bulking phenomenon to prevent damage of a switching part. Also, the responsiveness of the valve can be improved.

TECHNICAL FIELD

[0001] The present invention relates to a suction valve of areciprocating compressor and particularly, to a suction valve of areciprocating compressor, capable of evenly distributing a stress whichis generated in the process of opening and closing a gas flow path inwhich gas flows without being concentrated in a location and improvingresponsiveness.

BACKGROUND ART

[0002] Generally, a compressor is a device for compressing fluid. Thecompressor is divided into a rotary compressor, a scroll compressor anda reciprocating compressor according to compressing methods.

[0003] The reciprocating compressor includes a motor unit for generatinga linear reciprocating driving force and a compression unit forreceiving the driving force of the motor unit and compressing gas.

[0004] In the reciprocating compressor, as a current is applied to themotor unit, the linear reciprocating driving force generated at themotor unit is transmitted to the compression unit, thereby sucking,compressing, and discharging refrigerant in the compression unit.

[0005]FIG. 1 is a view illustrating one example of the compression unitof the reciprocating compressor. As shown in FIG. 1, the compressionunit of the reciprocating compressor includes a cylinder 10 providedwith a through hole 11 therein which makes a compression space Ptherein; a piston 20 inserted to the through hole 11 of the cylinder 10for a linear movement and provided with a hollow channel F therein; anda discharge valve assembly 30 engaged to an end portion of the cylinder10 for covering the through hole 11.

[0006] The piston 20 includes a head portion at one side of a bodyportion 21 having a predetermined length, and a connecting portion 23connected to the motor unit at the other side of the body portion 21.

[0007] Also, the piston 20 is provided with a hollow channel F formed topenetrate the piston 20 for making the refrigerant flow, and the hollowchannel F includes a gas passage 24 having a predetermined depth at acenter of the body portion 21 and a suction hole 25 penetrating the headportion 22 to be connected to the gas passage 24.

[0008] Also, a suction valve 40 is mounted at a front end surface S ofthe piston head portion 22 for controlling the refrigerant flowing tothe hollow channel F by opening and closing the suction hole 25.

[0009] The discharge valve assembly 30 includes a discharge cover 31engaged to cover an end portion of the cylinder 10, a discharge valve 32inserted in the discharge cover for opening and closing a compressionspace P formed by the piston 20 and a through hole of the cylinder 10,and a valve spring 33 for elastically supporting the discharge valve 32.

[0010] In the compression unit of the reciprocating compressor, a lineardriving force of the motor unit is transmitted to the piston 20, so thatthe piston 20 has a linear reciprocation in the cylinder 10.

[0011] In said process, as shown in FIG. 2, if the piston 20 movestowards a lower dead point a, the discharge valve 32 is in contact tothe end portion of the cylinder 10 by a pressure difference to close thecompression space P, and the suction valve 40 engaged to the piston 20is bent to open the suction hole 25. According to this, refrigerantflows through the hollow channel F of the piston 20 and is sucked to thecompression space P of the cylinder 10.

[0012] Then, if the piston 20 moves from the lower dead point a to anupper dead point b, the suction valve 40 is straightened by a pressuredifference as it was, and compresses the refrigerant sucked in thecompression space P of the cylinder 10 under a state that the suctionhole 25 of the hollow channel is blocked. Subsequently, if the piston 20reaches to the upper dead point b, the discharge valve 32 is opened,thereby discharging the compressed refrigerant. The said process iscontinuously repeated to compress gas.

[0013] In the meantime, the suction valve 40 mounted to the front endportion S of the piston 20 for opening and closing the hollow channel Fby repeating curving and straightening by a pressure difference due to amovement of the piston 20 should have an excellent responsiveness of avalve to suck and compress the refrigerant, and should minimize a stressconcentration to prevent damage.

[0014] As an example of the suction valve 40 of the reciprocatingcompressor currently being developed, as shown in FIG. 3, the suctionvalve 30 formed as a thin circle plate corresponding to the front endportion S of the head portion 22 of the piston includes a fixation point41 formed at the center of the circle plate and a cut off C having apredetermined width in the circle plate as an opened curved line to benda part of the circle plate on the basis of the fixation point 41.

[0015] The cut off C of the opened curved line includes an innercircular curved line portion makes a circle form to surround thefixation point 41, and an outer circular curved line portion 43prolonged from the inner circular curved line portion 42 and to beopened outwardly.

[0016] The suction valve is composed of a fixation part 44 correspondingto the fixation point 41 side by the inner circular curved line portion42 and the outer circular curved line portion 43, and an open/close part45 of the opposite side of the fixation part 44.

[0017] The open/close part 45 has a cantilever shape and a width thereofbecomes narrower towards an inner end portion of the inner circularcurved line portion 42.

[0018] Under a state that the open/close part 45 of the suction valve 40is located at an end surface of the piston 20 to block the hollowchannel F of the piston 20, the fixation point 41 thereof is welded tothe front end surface S of the piston and fixed-engaged to the piston20.

[0019] The engaged suction valve 40 opens and closed the hollow channelF by the open/close part 45 which is bent and straightened under a statethat the fixation point 41 is fixed by a pressure difference as thepiston 20 reciprocates.

[0020] However, in the process that the open/close part 45 is bent andstraightened, since the open/close part 45 of the suction valve foropening and closing the hollow channel F of the piston 20 is formed as acantilever form, as shown in FIG. 4, a stress is concentrated to a neckportion of the open/close part 45, that is, an inner end portion of thecut off C for forming the open/close part 45. According to this, whenthe opening and closing operations are continuously performed or theopen/close part 45 is opened, the valve is destroyed.

TECHNICAL GIST OF THE PRESENT INVENTION

[0021] Therefore, an object of the present invention is to provide asuction valve of a reciprocating compressor capable of evenlydistributing a stress generated in the process of opening and closing agas flow path in which gas flows without being concentrated in alocation and improving responsiveness.

DETAILED DESCRIPTION OF THE INVENTION

[0022] In order to achieve the above objects, there is provided asuction valve of a reciprocating compressor including a fixation part,which receives a driving force of a reciprocating motor, and isfixed-combined to the front end surface of a piston performing a linearreciprocal movement in the cylinder; an open/close part for opening andclosing a hollow channel formed to penetrate the piston having a certainarea, and a plurality of arms for connecting the open/close part and thefixation part to make the open/close part behave in a certaindisplacement section by having the fixation part as a fixed point.

BRIEF DESCRIPTION OF THE DRAWINGS

[0023]FIG. 1 is a cross-sectional view showing a compression unit of areciprocating compressor.

[0024]FIG. 2 is a cross-sectional view showing an operation state of thecompression unit of the reciprocating compressor;

[0025]FIG. 3 is a perspective view showing a suction valve of areciprocating compressor which is currently developed;

[0026]FIG. 4 is a front view showing a stress distribution state of asuction value of the above reciprocating compressor;

[0027]FIG. 5 is a cross-sectional view showing a compression unit inwhich the suction valve of a reciprocating compressor in accordance withthe present invention is provided;

[0028]FIG. 6 is a perspective view showing the suction valve and apiston head portion of the reciprocating compressor in accordance withthe present invention;

[0029]FIG. 7 is a front view showing a modification example of thesuction valve of the reciprocating compressor in accordance with thepresent invention;

[0030]FIG. 8 is a front view showing a modification example of thesuction valve of the reciprocating compressor in accordance with thepresent invention;

[0031]FIG. 9 is a front view showing a modification example of thesuction valve of the reciprocating compressor in accordance with thepresent invention;

[0032]FIG. 10 is a front view showing a modification example of thesuction valve of the reciprocating compressor in accordance with thepresent invention;

[0033]FIG. 11 is a front view showing a modification example of thesuction valve of the reciprocating compressor in accordance with thepresent invention;

[0034]FIG. 12 is a front view respectively showing the othermodification example of the suction valve of the reciprocatingcompressor in accordance with the present invention; and

[0035]FIG. 13 is a front view respectively showing the othermodification example of the suction valve of the reciprocatingcompressor in accordance with the present invention.

MODE FOR CARRYING OUT THE PREFERRED EMBODIMENTS

[0036] The present invention will now be described with reference toaccompanying drawings.

[0037] First, the reciprocating compressor includes a motor unit forgenerating a linear reciprocating driving force, and a compression unitfor receiving the driving force of the motor unit and compressing gas,wherein the motor unit is made of a reciprocating motor.

[0038]FIG. 5 is a cross-sectional view showing a compression unit inwhich the suction valve of a reciprocating compressor in accordance withthe present invention is provided. As shown in FIG. 5, the compressionunit includes a cylinder 10 provided with a through hole 11 therein, thethrough hole making a compression space P therein; a piston 20 insertedto the through hole 11 of the cylinder 10 to have a linear movement andprovided with a hollow channel F therein; and a discharge valve assembly30 engaged to an end portion of the cylinder 10 to cover the throughhole 11 for opening and closing the through hole 11.

[0039] The compression space P is formed by the through hole 11, thepiston 20, and the discharge valve assembly 30 of the cylinder.

[0040] The piston 20 includes a head portion at one side of a bodyportion 21 having a predetermined length, and a connecting portion 23connected to the motor unit at the other side of the body portion 21.

[0041] Also, the piston 20 is provided with a hollow channel Fpenetrating the piston 20 for making the refrigerant flow, and thehollow channel F includes a gas passage 26 having a predetermined depthat a center of the body portion 21 and a suction hole 27 penetrating thehead portion 22 to be connected to the gas passage 26.

[0042] Also, a suction valve 50 of a thin plate is mounted at a frontend surface S of the piston head portion 22 for opening and closing thesuction hole 27 of the hollow channel F.

[0043] The discharge valve 50, as shown in FIG. 6, a fixation part 51having a predetermined area and engaged to a front end portion S of thepiston; a open/close part 52 having a predetermined area and penetratingthe piston 20 for opening and closing the hollow channel; and aplurality of arms 53 and 54 for connecting the open/close part 52 andthe fixation part 51 and making the open/close part 52 move in apredetermined displacement section by having the fixation part 51 as afixation point.

[0044] The arms 53 and 54 are formed symmetrically on the basis of aconnection line between a center of the fixation part 51 and a center ofthe open/close part 52.

[0045] That is, the fixation part 51 having a circular area is formed,and the first and second arms 53 and 54 having a circular arc shapehaving a predetermined width and length are respectively prolongedtowards both sides of the fixation part 51, then, the open/close part 52having a predetermined area is formed.

[0046] A width of the first and second arms 53 and 54 can be formeduniformly or differently. That is, the width of the first and secondarms can be wide towards the open/close part 52 or narrow.

[0047] The fixation part 51, the first and second arms 53 and 54, and anouter surface of the open/close part 52 make a circular shape, and anouter diameter of the circular shape is smaller than that of the frontend surface of the piston 20.

[0048] Also, the fixation part 51, the first and second arms 53 and 54,and an inner surface of the open/close part 52 make a close space. Thefixation part 51 is engaged to the front end portion S of the piston 20by bolting or welding.

[0049] The open/close part 52 and the plurality of arms 53 and 54, asshown in FIG. 7, are formed to have an initial displacement by beingbent from the front end portion S of the piston 20 to a front endportion of the cylinder 10 with a predetermined amount.

[0050] The fixation part 51 of the suction valve 50 engaged to the frontend portion S of the piston 20 is preferably engaged by being located toa center of the front end portion S of the piston 20.

[0051] The suction holes 27 formed at the head portion of the piston 20are plural, and the open/close part 52 of the suction valve 50 is formedto have an area to block the plurality of suction holes 27.

[0052] That is, the hollow channel F includes the gas passage 26 formedat the body portion of the piston, and the plurality of suction holes 27penetrating the head portion 22 of the piston 20. Three suction holes 27are shown in the drawings.

[0053] Also, as shown in FIG. 8, an edge of the suction hole 27 ispreferably fillet (C) by rounding. As an example of its modification,the edge of the suction hole 27 can be chamfered as a straight line.

[0054] A modification example of the fixation part 51, as shown in FIG.9, includes a fixation surface 51 a having a predetermined area andfixed by bolting or welding, and a protruded portion 51 b extended fromthe fixation surface 51 a with a predetermined area and located at aspace formed by the plurality of arms 53 and 54

[0055] A modification example of the open/close part 52, as shown inFIG. 10, includes a cutting portion D cut off at an outer portion of thesuction valve according to a shape of the suction hole 27 of the hollowchannel F formed at the front end surface S of the piston 20.

[0056] Another modification of the open/close part 52, as shown in FIG.11, includes a cutting portion D cut off at an inner portion of thesuction valve according to a shape of the suction hole 27 of the hollowchannel F formed at the front end surface S of the piston 20.

[0057] As another embodiment of the present invention, as shown in FIG.12, the suction valve includes a fixation part 51 engaged to the frontend portion S of the piston 20; a open/close part 52 having apredetermined area for opening and closing a hollow channel Fpenetrating the piston 20; and four arms 53 for connecting theopen/close part 52 and the fixation part 51 and making the open/closepart 52 move in a predetermined displacement section by having thefixation part 51 as a fixation point.

[0058] As another embodiment of the present invention, as shown in FIG.13, the suction valve includes two open/close parts 52 and 52′ locatedat the front end portion S of the piston 20 provided with two gassuction holes 27 for opening the two suction holes 27; and two arms 53and 54 for connecting the fixation part 51 engaged to the front endportion S of the piston 20 and the two open/close parts 52 respectively.

[0059] An unexplained code 30 denotes a discharge valve assembly, 31denotes a discharge cover, 32 denotes a discharge valve, and 33 denotesa valve spring.

[0060] Hereinafter, operations and effects of the suction valve of areciprocating compressor in accordance with the present invention willbe explained.

[0061] First, if the piston 20 receives a driving force of the motorunit and reciprocates linearly in the cylinder 10, the suction valve 5engaged to an end portion of the piston 20 is bent and straightenedrepeatedly by a pressure difference. According to this, refrigerant issucked, compressed, and discharged repeatedly through the hollow channelF of the piston 20, that is, the gas passage 26 and the suction hole 27.

[0062] In said process, in case that the suction valve 50 opens thesuction 27 of the hollow channel F formed at the front end portion S ofthe piston 20 by a pressure difference, the plurality of arms 53 and 54and the open/close part 52 are bent by being fixed by the fixation part51 of the suction valve 50, thereby opening the suction hole 27.

[0063] Also, in case that the suction valve 50 closes the suction 27 ofthe hollow channel F formed at the front end portion S of the piston 20by a pressure difference, the plurality of arms 53 and 54 and theopen/close part 52 are straightened by being fixed by the fixation part51 of the suction valve 50, thereby closing the suction hole 27.

[0064] In the meantime, as the plurality of arms 53 and 54 having acantilever shape are bent and straightened under a state that thesuction valve 50 is fixed by the fixation part 51, a stress occurs. Atthis time, the stress is distributed to the plurality of arms 53 and 54evenly, so that the stress is not excessively concentrated to oneconventional arm. Also, the plurality of arms 53 and 54 are formedsymmetrically, thereby distributing the stress more evenly.

[0065] Also, since the open/close part 52 of the suction valve 50 andthe plurality of arms 53 and 54 have a predetermined displacement withthe end portion surface S of the piston 20, the suction hole 27 isopened and closed more smoothly. That is, responsiveness of the valve isimproved.

[0066] Also, since the fixation part 51 of the suction valve 50 providedwith the fixation surface 51 a and the protruded portion 51 b reducesthe inner space, a dead volume of the compression space is reduced,thereby enhancing a compression performance.

[0067] Also, the suction holes 27 of the piston 20 opened and closed bythe suction valve 50 are plural, a bulking phenomenon is prevented,thereby preventing damage of the valve.

[0068] The bulking is a phenomenon that the open/close part 52 of thesuction valve 50 is sucked to an inner side of the piston by the suctionhole 27 of the piston 20 when a great pressure is added to the suctionvalve 50 as the piston 20 reaches to the upper dead point in a processof the compression.

[0069] Also, since the suction holes 27 are formed with a plurality ofsmall holes, an amount that the suction valve 50 is modified by apressure is less than when the suction holes 27 are formed with onelarge hole, thereby preventing damage of the suction valve 50.

[0070] Besides, since the edge of the suction holes 27 is chamfered, thesuction valve 50 is prevented from being damaged by the edge of thesuction holes 27 at the time of the bulking phenomenon.

[0071] Also, since the open/close part 52 of the suction valve is cutoff at an outer portion thereof according to a shape of the suctionholes 27, a gap is obtained at the compression space P of the cylinder,that is, between the inner circumference surface of the cylinder throughhole and the open/close part 52 of the suction valve 50. According tothis, refrigerant is smoothly sucked to the compression space P even incase that the valve is opened, thereby increasing a suction amount ofthe refrigerant.

INDUSTRIAL APPLICABILITY

[0072] As so far described, the suction valve of the reciprocatingcompressor of the present invention is bent and straightened by apressure difference as the piston receives a driving force of thereciprocating motor and linearly reciprocates in the cylinder, therebysucking refrigerant gas. In said process, a stress generated at thevalve is evenly distributed and the bulking phenomenon is minimized, sothat a damage is prevented to enhance reliability. Also, responsivenessof the valve becomes excellent and the refrigerant is smoothly sucked tothe compression space of the cylinder, thereby enhancing a compressionperformance of the refrigerant.

1. A suction valve for reciprocating compressor, comprising: a fixationpart which receives a driving force of a reciprocating motor and isengaged to a front end surface of a piston performing a linearreciprocation in the cylinder; an open/close part having a predeterminedarea for opening and closing a hollow channel formed to penetrate thepiston; and a plurality of arms for connecting the open/close part andthe fixation part and making the open/close part move in a certaindisplacement section by having the fixation part as a fixed point, inwhich a stress generated by a movement of the open/close part isdistributed to the plurality of arms.
 2. The valve of claim 1, whereinthe arms are composed of two.
 3. The valve of claim 2, wherein the twoarms are symmetrical to each other on the basis of a connection linewhich connects a center of the fixation part and a center of theopen/close part.
 4. The valve of claim 1, wherein the fixation partinclude: a fixation surface having a predetermined area and fixed bybolting or welding; and a protruded portion 51 b extended from thefixation surface 51 a with a predetermined area and located at a spaceformed by the plurality of arms.
 5. The valve of claim 1, wherein thesuction holes formed at a front end portion of the piston for forming apart of the hollow channel and opened and closed by the open/close partare plural.
 6. The valve of claim 5, wherein an edge of the suction holeis filleted by a rounding or chamfered by a straight line.
 7. The valveof claim 1, wherein the open/close part is cut off at an outer portionaccording to a shape of the suction hole of the hollow channel formed atthe front end portion of the piston.
 8. The valve of claim 1, wherein anouter diameter formed by the open/close part, the fixation part, and thearms is smaller than that of the front end portion of the piston.
 9. Thevalve of claim 1, wherein the open/close part and the plurality of armsare formed to have an initial displacement by being bent from the frontend portion of the piston to a front end portion of the cylinder with apredetermined amount.
 10. The valve of claim 1, wherein the fixationpart is located at a center of the front end portion of the piston. 11.A suction valve of a reciprocating compressor, in the reciprocatingcompressor attached to an upper surface of a piston which reciprocatesby a reciprocating motor for controlling gas sucked through a hollowchannel in the piston, the suction valve comprising: a piston having aplurality of gas suction holes; at least one open/close part fixed to anupper end portion of the piston for corresponding to the gas suctionholes; a fixation part engaged to the piston; and one or plural arms forconnecting the one or plural open/close parts to the fixation part.